Method for making pure hydrogen



y 1 A. R. STRY\KER 2,200,607

METHOD FOR MAKING PURE HYDROGEN Filed Oct. 18, 1957 /pzameaoy g I waeagsm/ I INVENTOR 6155a: 12. {/z/y E BY ATTORN EY Patented May 1 4, 1940 PATENT OFFICE 2,200,007 METHOD FOR MAKING PURE HYDROGEN Albert R. Stryker, Lawrenceburg, 1nd,, assignor of one-fourth to Chester Tietig, Covington, Ky.

Application October 18, 1937, Serial No. 169,662

6 Claims.

This invention relates to a process and apparatus for making hydrogen of exceptional purity. The product of my process is so pure that it may be used for hydrogenating oils to make edible fats.

Heretofore expensive purification steps have been necessary in order to make hydrogen which has been made by thermochemical processes, fit for use in hydrogenation. Consequently, electrolytic or catalytic methods, which are less expeditious and more expensive, have been favored for large scale hydrogenation projects.

Briefly stated, my process comprises forcing a crackable alipathic hydro-carbon for example, methane ethane, propane, butane orhigh grade natural gas through a primary cracking zoneof heated checkerbrick then through a deep bed of solid carbonaceous fuel maintained at least partially at incandescence and withdrawing the cracked gas from the lower end of the fuel bed, and then recycling the free hydrogen-rich gas thus obtained again through the checker work and the fuel bed until the desired degree of purity 'has\been obtained. The product may then be stored while another cycle is run or the entire yield may be recycled- It is of course necessary to reheat the checkerwork and the fuel bed at intervals by blasting with air and the apparatus must be purged of air after such blowing, so as to avoid nitrogen compounds and CO in the hydrogen, which are objectionable.

Referring to the drawing, the figure is a diagrammatic elevation of the apparatus partly in longitudinal section.

10 is a generator, refractory lined, having a conical bottom ll, a'grate l2, a bottom discharge l3 and a side charging chute I4. Suitable. clinkering doors l5 are provided. A bedof fuel l6 preferably of coke, is carriedwithin the retort and should be of at least four feet in depth, but

a depth of about ten feet is preferable. Extending vertically above the "generator there is a dome H, the interior of which is refractory lined and communicates with the interior of the generator. The lower part of the dome, say from one-third to one-half of its height, is filled with refractory brick checkwork, 9, which comprises about 50% of voids. I

At-the top of dome II, there is a pipe [9 for 0 the admission of the hydro-carbon to be cracked.

The process and apparatus will be described as for handling butane, but any skilled chemical engineer in possession of this disclosure can regulate conditions to use the others named, or even commercial gasoline, kerosene, gas oil or distillate. Pipe I9 therefore handles liquid butane which may be shut off in the pipe or allowed to flow by the action of a snap valve 20 controlled, by a diaphragm 2|, which-is in turn controlled by a pressure existing within a dome v II, but

.which is so communicated to the diaphragm through a small pipe 22. "Air is supplied to the generator by means of a horizontal pipe 24 in which there is both a conventional shut off valve 25 and a butterfly valve 26. A steam supply pipe 21 enters air pipe 24 in advance of the shut off valve 25. Behind butterfly valve 26 there is a riser pipe 28 for ,the delivery of secondary and tertiary air to the dome. The purpose of the secondary air is to burn-the producer gas made by blasting the fuel bed and also the carbon from the checker Work during the heating operations. This combustion creates considerable carbon monoxide which 'is subsequently burned to the dioxide with the tertiary air. Pipe 29 is therefore arranged to enter just below the checker-work to deliver secondary air and pipe 30 just above the cheekerwork to deliver the tertiary air. Pipe 29 contains shut off valve 3| and pipe 30 contains a shut off valve 32 and a butterfly valve 33 just behind it. Steam may be supplied to pipe 29 through a pipe 34 which enters riserpipe 28 opposite pipe 29. In pipe 29 there is a butterfly valve 55 in addition to a shut off valve.

The exit of waste gases from the dome I! may occur through a flue pipe or stack 35 in which there is a shut off valve 36,.or gases may be recycled from the conical bottom 'II to the dome l'l through second riser pipe 31 in which there is a shut off valve 38 in the lower portion near the generator, an exhauster 39 and a shut off valve 40 and butterfly valve 4|. near the dome. A convenient arrangement for the entire apparatus is to have the operating floor of the building at the approximate level of the top of the conical portion of the generator and below the grate therein. Such floor, 42, in the drawing will be adapted to, support the blower 23 and exhauster 39 at a convenient height.

At a point above exhauster 39 a delivery pipe 43 containing a shut off valve and a butterfly valve 45 taps riser pipe 31 and leads to below the liquid level 46 of wash box 41 which rests upon the operating floor. This box has an outlet pipe 45 in which there is a shut off valve 49.

' For purging the apparatus there is a bottom inlet pipe 50 having a shut off valve 5| which enters riser pipe 31 between valve 38 and the The cycle of operations is as follows: The gen erator having been filled with maintenance fuel,

(i. e. that fuel which is charged into the generator for the'purpose of providing a bed of hot carbon) and valves 25, 26 and 36 being open and all the rest closed, thefuel is ignited and blown with air from the blower 23 until the fuel bed is at approximate incandescence. Valve 3| is opened andsecondary air admitted through pipe 29 to allowproducer gas to burn and heat the checker work. Tertiary air is admitted also through pipe 30 by opening valves 32 and 33. The amounts of secondary and tertiary air are regulated by means of butterfly 33 and no more is admitted than is necessary to burn the carbon monoxide below and above the checkerwork to carbon dioxide. Both air inlets are so arranged that the stream of air is directed substantially tangentially to the shell of the generator.

After incandescence to the extent of about 2600 F. has been attained in the fuel bed and the checker brick in the dome has attained about 2000 F.- the operation of purging may then begin.

Blower 23 is then shut down and valves 25, 3| and 32 are closed. Suflicient steam is now admitted through pipe 21 to purge air from the base below the grate only. Butane gas is then admitted through pipe 50 so as to.,crack to hydrogen within the fuel bed, and this hydrogen rises and purges all blast products through the open stack 35.

After pure hydrogen only is passing up stack 36, as indicated by the test flame 53, stack valve 36 is closed and liquid butane is allowed to flow into pipe l9. Valves 38 and 40 are now opened simultaneously, butterfly 4| being partly open. Exhauster 39 is started which recycles hydro-carbon purge gas to the top of the dome to be adjusted on passage through the hot checkerwork. ,Valve 44 is then opened and butterfly 45 cracked to allow hydrogen to pass into the wash box 41, the butterfly valve 45 in pipe 33 being used to control the pressure in the retort. It is set to exceed the back pressure of the wash box. Due to the fact that there is a thermal expansion of the butane gas after it is fed in, and later undergoes secondary expansion due to the swell in volume caused by cracking, it is necessary that the apparatus be built to be able to withstand high pressure. A predetermined amount of butane is admitted per cycle to reach the maximum pressure desired to accommodate the expansion in volumes described. The setting of butterfly 45 should be high enough to hold these pressures. The setting of butterflies 45 and 4! are controlled in accordance of the indications of the test flame 52 or suitable mechanical or chemical testing devices. If this shows that pure hydrogen is not being produced the butterflies are opened further to recycle more gas.

Fluid hydrocarbon material is admitted through the top of the dome in quantities governed by the diaphragm regulator 2i which allows sufiicient liquid butane to enter the retort to replace the butane lost by the exit of hydrogen from the previous cycle through pipe 48 to a gas holder (not shown).

Operation is continued until the drop in the temperature of the fuel bed requires excessive recycling through pipe 31 by reason of the fuel bed not being hot enough to crack the hydrocarbon completely. When this condition occurs, the butane supply is shut off by a valve 54 and valves 40 and 38 are closed. Exhauster 39 is shut down.

Purging steam is admitted through pipe 21 sumcient to purge only the hydrogen from below the grate. Blower 23 is now operated, then stack valve 36 and likewise butterfly 26 and secondary and tertiary air is admitted by means of valves 3| and 32 as desired. When this blasting or reheating step is complete the hydrogen making cycle is again restarted. Very little maintenance fuel will be required because almost all of the fuel consumed in the process will be carbon which has been deposited in the interstices of the fuel bed by the cracking of the butane.

I claim as my invention:

1. The method of commercially producing substantially pure hydrogen gas which comprises providing a bed of solid fuel heated to incandescencein a closed reaction chamber, passing a crackable aliphatic hydrocarbon through the incandescent bed of fuel so as to reduce the hydrocarbon to a mixture of completely and incompletely decomposed hydrocarbon gases, recirculating said mixture of hydrocarbon gases through the same incandescent bed of fuel until complete decomposition results and finally withdrawing the pure hydrogen from said chamber.

2. The method of commercially producing substantially pure hydrogen gas which comprises providing a bed of solid fuel heated to incandes- 'cence in a closed reaction chamber, passing a crackable aliphatic hydrocarbon through the incandescent bed of fuel so as to reduce the hydrocarbon to a mixture of completely and incompletely decomposed hydrocarbon gases, recirculating said mixture of hydrocarbon gases through the same incandescent bed of fuel until complete decomposition results, withdrawing the pure hydrogen from said chamber, restoring the bed of fuel to incandescence by air-blasting, purging said chamber in sequence with steam, and with a hydrocarbon gas which produces hydrogen upon cracking, and continuously repeating the above cycle of operations.

3. The method of commerciallyproducing substantially pure hydrogen gas which comprises providing a bed of solid carbonaceous fuel in a closed reaction chamber, heating said fuel to incandescence by supplying oxygen thereto, passing a crackable aliphatic hydrocarbon downwardly through a highly heated zone of the chamber and through the incandescent bed of fuel so as o reduce the hydrocarbon to a mixture of completely and incompletely decomposed hydrocarbon gases, forcibly recirculating said mixture of hydrocarbon gases through the same highly heated zone 6. The method defined in claim 1 in which the aliphatic hydrocarbon is butane introduced into the reaction chamber in liquid form.

- ALBERT R. STRYIGZR. 

